Continuous loop restraint systems for restraining a person in a vehicle seat are known in the art and such systems are gaining popularity. In such a system, one end of the belt is attached to the floor and the other end is attached to the ceiling or door post of the vehicle. The webbing passes through a connector or releasable anchor adapted to be attached to the floor on the side of the user opposite the permanent floor anchor. Either end could be attached to a retractor, but for reasons set forth below, it is advantageous that the retractor be mounted in the ceiling or the door post position rather than on the floor.
When the vehicle is unoccupied, the webbing is fully retracted on the retractor and the remaining webbing runs directly from the floor anchor through the connector to the retractor assuming the retractor is in the preferred door post or ceiling position. When the restraint system is to be used, the occupant of the vehicle pulls on the connector to withdraw webbing from the retractor. Sufficient webbing passes through the connector so that there is enough webbing to cross the occupant's lap, and the connector or releasable anchor is anchored to a releasable buckle on the other side of the seat from the anchored end of the webbing.
A continuous loop system allows the use of a single retractor. By using a continuous loop system the three point tongue plate is unnecessary, and the extra cost of cutting and sewing the belt at the tongue plate can also be eliminated. The main drawback, however, with such a system is the tendency for the lap belt portion to be loose around the pelvis. In order for the lap belt portion to effectively restrain the lower part of the user, it must fit tightly around the pelvis so that the large bones in the hip absorb the crash forces transmitted by the belt. If it is loose and rides up into the abdominal portion where there is minimal skeletal protection, the belt can injure internal organs during a crash.
Generally, the retractors used in present safety belt systems are not strong enough to pull the lap belt portion of the webbing through the connector and up into the shoulder portion. Even if such a retractor were used, the resultant pull on the shoulder portion of the webbing would be too strong and the user would be constantly forced back into his seat. It is not important that the shoulder strap be tight around the occupant's chest, and it should be loose enough to permit him to lean forward and reach all the vehicle controls. Moreover, for the user's comfort, clips and tensionless retractors, the latter being taught by U.S. Pat. No. 3,550,875 which exerts no force in normal operation to the shoulder strap, are now provided in many vehicles to prevent the shoulder strap from pulling against the user.
It has also been proposed to provide a one-way fitting on the connector in order to prevent the webbing from moving through the connector and loosening the lap belt portion. Such systems are proposed in the patent to Sharp U.S. Pat. No. 3,258,293 and Carter U.S. Pat. No. 3,606,455. In many prior systems, the lap belt must be manually tightened by pulling the shoulder strap through the one-way connector or the connector must be manipulated so that the retractor will tighten the belts. If the strap is not pulled tight enough, injury can result. Another major drawback is that when the seat location or size of passenger is modified, the lap belt portion may have to be lengthened. With one-way connectors, it may be time consuming and somewhat difficult to pull the lap belt portion the wrong way through the one-way connector.
Therefore, it is an object of the invention to provide a continuous loop restraint system which will automatically provide a tight lap belt even when used with a variety of retractors. A further object of the invention is to provide such an automatic system which can be adapted for different sized occupants and different seat locations of the vehicle without any manual adjustments to the system. A further object is to provide a system which can be completely retracted on the vehicle retractor to remain flush against the side of the vehicle and yet can be automatically deployed without any manual adjustments to maintain a tight lap belt. These and other objects are explained in the foregoing description.